Spin-on, twist-on, type filters are used in numerous liquid and pneumatic applications thoughout the agricultural, mobile, commercial and industrial market places. Prior art spin-on disposable filter products are manufactured using a thin gauge metal can, or housing, made by deep-draw forming malleable metals. This technique limits the structural capabilities of current spin-on, twist-on, type disposable products to the production capabilities of the metal forming industry and to the molecular characteristics of a limited number of specific malleable metals. Prior art uses a stamped steel or cast cover plate to secure the can to a mounting and distribution head assembly. This plate typically has a threaded center hole and is spot welded and/or crimp sealed to a deep-drawn can. These techniques for sealing and connecting the can to the plate, plus the structural limits of thin gauge malleable metals, generally restrict the applicational uses of prior art spin-on, twist-on, disposable filters. Some new high pressure, high-strength, disposable filter housings with burst pressure ratings in the 1,000 psi range have been developed for some narrowly defined markets and applications. However, even these newer high-strength filters remain applicationally limited because of their continued use of deep-drawn metal cans.
Another typical design common to prior art spin-on, twist-on, type filters is the necessity of manufacturing a separate filter element to be installed, along with various separator devices, into the filter housing. A separate and segregated filter element cartridge is subject to different cyclical operational loads than those experienced by the filter housing. Current internal filter cartridge designs do not properly protect against seal distortion or wear deterioration caused by applicational flow dynamics and vibration. Such seal distortion and wear deterioration lessens a filters contamination removal efficiency by allowing contaminated fluid to by-pass the filter medium.
Examples of prior art limitations can be found in U.S. Pat. No. 4,719,012 and more recently U.S. Pat. No. 4,743,374 issued as an improvement over earlier U.S. Pat. No. 4,369,113. Each of these designs incorporates the continued use of a deep-drawn thin gauge metal can having a separate and segregated internal filter cartridge. Rated fatigue pressure is in the 500 psi range and burst pressure ratings are in the 1,000 psi range. These prior art pressure limitions leave a major product void in the high-strength disposable filter market.
Thus, a need exists for an improved structural spin-on, twist-on, style disposable filter with higher pressure capacity, a better fatigue rating, one that eliminates the need for a segregated internal filter cartridge, and a filter product that decreases by-pass losses caused from distorted or deteriorated internal filter seals. The present tube invention is designed to overcome one or more of the problems as set forth above.